1. Field of the Invention
The present invention relates generally to electro-monorail systems (EMS) that interact with vertical-lift-stations (VLS), and more particularly to an assembly for aiding the alignment of and interlocking the EMS and VLS in a fixed condition.
2. Discussion of Prior Art
Electro-monorail systems (EMS) have been developed to facilitate the assembly, fabrication and inventory of a multi-step multi-nodal process. In the automotive industry, for example, EMS are frequently utilized to facilitate the stamping, welding, painting, or general assembly processes of an auto-body work in progress. These systems utilize a main rail to interconnect a plurality of nodes, and support a carrier that is propelled from node to node by continuous electric potential within the rail. As such, the load carrying main rail includes a series of conductive slats and shoes followed by a grounding slat. The carrier includes a series of front and rear bushings for receiving the oscillating electric current, and wheels which rollingly engage raceways defined by the main rail. Where overhead EMS configurations are provided, each node typically features a vertical lift station (VLS) that translates into and out of an operable position, wherein a VLS rail is positioned adjacent the EMS main rail. Once in position, the carrier is able to travel upon the VLS rail, so as to be lowered within the work cell. Finally, when the work is complete, the VLS is raised to the operable position, so that the carrier can proceed to the next station.
The entry and exit of the carrier upon the VLS rail, however, present commonly experienced concerns caused by misalignment and/or deflection. More particularly, it is appreciated by those of ordinary skill in the art that as the carrier enters the VLS rail, the VLS descends a small yet significant dimension. This action by the VLS causes, among other things, the rear bushing of the carrier to drag on the main rail. By catching the end of the carrier, a downward force equal to the weight of the carrier and payload acts upon the end of the main rail. As a result, the relatively lightweight main rail, which is often formed of aluminum, may be caused to inelastically deform due to insufficient structural capacity. As the carrier exits the VLS, the descended configuration may cause the carrier to strike the EMS at the exit point, which may further cause inelastic deformation at the exit point. Meanwhile, the front and rear bushings of the carrier are often damaged from constant dragging and striking of the main rail.
Various measures have been implemented to structurally support and reduce misalignment and deflection at the EMS-VLS interface, including the addition of massive steel beams to reinforce the existing framework. These measures have achieved little success and have not been incorporated due to costs, work cell space, and inefficiency of operation. Instead, damaged EMS, VLS rail, and carrier components are typically allowed to undergo gradual degradation until replacement.
Thus, there remains a need in the art for an improved measure for reducing the likelihood of misalignment and deflection at an EMS-VLS interface, and the damages caused thereby.